## 6.2.1. Identifiers (Names)

An identifier that appears as an atom is a name. When the name is bound to an object, evaluating the atom yields that object. When a name is not bound, an attempt to evaluate it raises a  `NameError`  exception.

### Private Name Mangling

When an identifier that occurs literally in a class definition begins with two or more underscores and does not end with two or more underscores, it is considered a private name of that class. Private names are transformed into a longer form before code is generated for them. The transformation inserts the class name, with the initial underscores removed and a single underscore inserted, in front of the name.